1. Field of the Invention
The present invention relates to a method of detecting a biomaterial using a combination of a filtering characteristic of a membrane and signal measurement of an electrode by forming the electrode on the filtering membrane by screen printing.
2. Discussion of Related Art
Quantitative analysis of a biomaterial is an important technique used in foods, medicine and diagnosis. In particular, rapid detection of microorganisms is a very important technique in diagnosis of food poisoning bacteria, detection of environmentally harmful bacteria and infections, and diagnosis of pathogenic viruses. As a generally and widely used method of examining for the presence and concentration of pathogenic materials (microorganisms, proteins, etc.), a colony method, a DNA probe method, and an immunoassay method are widely used (Jay J M. Modern Food Microbiology, 1986, 3rd, ed., p 95, Van Nostrand Reinhold Co., New York; Tenover F C., DNA Probes for Infectious Diseases, 1989, p 53 CRC Press, Boca Raton). The colony method is a method of counting the number of colonies formed by microorganisms cultured in a selective medium having ingredients allowing only microorganisms from a sample to survive and be detected. This is a very accurate but time-consuming method, and there is difficulty in selecting a medium with respect to a microorganism. The DNA probe method is a method including a real time polymerase chain reaction (PCR) and nucleic acid hybridization, and is used to detect DNA in a cell by nucleic acid conjugation after microorganisms are disrupted by a physicochemical method. This is faster than the colony method in detecting microorganisms. However, it needs expensive PCR equipment and requires separate incubation to obtain high sensitivity when a small amount of microorganisms is detected (Ninet, B et al., Appl Environ Microbiol 58:4055-4059, 1992). If incubation is not included, dead cells may be detected, which leads to inaccurate results. In addition, when PCR is performed, a range of detection errors becomes wide due to frequent false-positive results, and thus it is possible to decrease reliability of the analysis. The immunoassay method uses an antigen-antibody binding reaction. An enzyme-linked immunosorbent assay (ELISA) using an antibody specifically reacting with a surface antigen of a microorganism to be detected is widely used. This is considered as an alternative to the above-described two methods since it achieves very high sensitivity in a short time.
The present invention is directed to providing a sensor that combines a measurement capability of an electrode and a filtering characteristic of a membrane, by forming the electrode on the filtering membrane.